Time Calculator
Add or subtract two durations in hours, minutes and seconds.
| Decimal hours | — |
|---|---|
| Total minutes | — |
| Total seconds | — |
| Operation | — |
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How the Time Calculator Works
Adding and subtracting time is fiddly because it’s base-60, not base-10 — you can’t just add the numbers. This calculator converts each duration to total seconds, does the arithmetic, then converts back to hours, minutes and seconds. Enter two durations, pick add or subtract, and it handles the carrying and borrowing for you.
It also gives the answer in decimal hours (handy for timesheets and billing) and in total minutes and seconds. Subtracting a larger time from a smaller one returns a negative duration, shown with a minus sign.
total seconds = hours×3600 + minutes×60 + seconds
Frequently Asked Questions
How do I add hours and minutes?
Convert each to total seconds, add them, then convert back. This calculator does it — 2h 30m + 1h 45m = 4h 15m.
What are decimal hours?
Time as a single number, where minutes are a fraction of an hour. 4h 15m is 4.25 decimal hours — the form payroll usually wants.
Can I subtract time?
Yes. Choose Subtract; if the result is negative the calculator shows it with a minus sign.